One day in mid-2017 my good friend, Radu Mantu, with whom I had already worked on many projects such as Dexter v2 came to me to ask if I am not interested in developing a prototyping project for a laser harp. He was going to be in charge of the software and I was only responsible for the product design and electronics. Since a laser harp (Figure 1) was a project I already had in mind for future development, I accepted immediately.
laser harp
Hardware Design
Displayed in Figure 2 are the laser strings visible in the dark. I used some laser diodes to emit the light signal and photoresistors in a voltage divider configuration to capture it. Also in Figure 3 you can observe the speaker of the whole system with the signal being fed from the microcontroller via a LM386 audio operational amplifier.
Product Design
Believe it or not, the hardest part of this project was the product design stage. Selecting some wooden square profiles, cutting them to the corresponding sizes, and assembling were relatively easy but time-consuming tasks. However, in order to accurately make the laser diode beam meet the photoresistor I had to develop a small calibration mechanism for each of them.
